
* {
    margin: 0px;
    padding: 0px;
}

#box {
    background-color: lawngreen;
    border: 5px solid;
    padding: 15px;
    margin: 10px;
}

#overflow {
    background-color: lawngreen;
    width: 200px;
    height: 60px;
    overflow: auto;   /*溢出：当内容超出容器可以容纳的范围时*/
    border: 5px solid black;
    margin: 0 auto;
}
